Search for an exotic S=-2, Q=-2 baryon resonance in proton-proton interactions at $\sqrt{s_{NN}}$ = 17.3 GeV

TL;DR

This paper reports an experimental search for exotic S=-2, Q=-2 baryon resonances in proton-proton collisions at 17.3 GeV, finding no evidence of such states despite increased data and optimized analysis.

Contribution

It provides the first high-statistics search for the \\Xim\\pim, \\Xim\\pip, \\Xip\\pim, and \\Xip\\pip resonances, challenging previous claims of their existence.

Findings

No signal of the \\Xim\\pim baryon resonance was observed.

The search used the upgraded \\NASixtyOne detector with optimized cuts.

Previous evidence from NA49 was not confirmed.

Abstract

Pentaquark states have been extensively investigated theoretically in the context of the constituent quark model. In this paper results of an experimental search for pentaquarks in the \Xim\pim, \Xim\pip, \Xip\pim and \Xip\pip invariant mass spectra in proton-proton interactions at $\sqrt{s}$=17.3~\GeV are presented. Previous possible evidence from the NA49 collaboration of the existence of a narrow \Xim\pim baryon resonance in p+p interactions is not confirmed with almost 10 times greater event statistics. The search was performed using the \NASixtyOne detector which reuses the main components of the NA49 apparatus. No signal was observed with either the selection cuts of NA49 or newly optimised cuts.